Flexureless multi-stable micromirrors for optical switching

• US 6,040,935 A
• Filed: 01/25/1999
• Issued: 03/21/2000
• Est. Priority Date: 01/25/1999
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Michalicek, M. Adrian
• Primary Examiner(s): Phan, James
• Application Number:
  US09/237,140
• Time in Patent Office: 421 Days
• Field of Search: 359/196-203, 359/212-214, 359/221, 359/223-226, 359/838, 359/848, 359/850, 359/871, 359/872
• US Class Current: 359/198.1
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 2203/0181 See-saws
• CPC Class Codes: B81B 2203/0307 Anchors
• CPC Class Codes: B81B 2203/058 Rotation out of a plane parallel to the substrate
• CPC Class Codes: B81B 5/00 Devices comprising elements which are movable in relation to each other, e.g. comprising slidable or rotatable elements
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An array of micromirror devices is fabricated using standard surface-micromachining techniques such that the reflective mirror surfaces are anchored by a trapped joint rather than by rigid support flexures. These devices are therefore multi-stable in actuation rather than continuous like typical micromirror devices in which the restoring spring force of the flexures is used to balance the force of electrostatic actuation. As a result, the flexureless micromirror can be actuated to specific stable positions that make it ideal for optical switching. Since no direct mechanical connection is required to support the mirror surfaces, these devices can be switched between stable positions in binary fashion and at higher speeds.

Claims

1. A flexureless micromirror device in a structural assembly, comprising a micromirror surface attached to one or more support columns, said support columns being anchored to the structural assembly of the device by a flexible locking joint, whereby the mirror surface is free to move about the joint and the mirror surface can be electronically switched between multiple stable positions.

2. The flexureless micromirror device in claim 1, whereby said micromirror is attached by a single central support column and said support column is anchored to said structural assembly by a pin-joint.

3. The flexureless micromirror device in claim 1, whereby a square micromirror is attached by four support columns at its four corners and said support columns are anchored to said structural assembly by pin-joints.